Hello all,

to start off I have a 98 TA with a t56 and 120k on the clock, bone stock except for a lid and loudmouth. I'm in the military and just got back home a couple months ago. Before I start mods I want to get this car running right, as I am having quite a few problems. I am bringing it in to have my guy take a look at it next week, but wanted the experts opinion on these matters first. Anyway... here we go...

1) There is a slight grinding noise when shifting into 2/3/4 & reverse. It is very faint, mostly I just feel it but I can just barely hear it too. I think I may just need to flush hydr. fluid, or possibly it is a synchro issue because it is sometimes hard to get into 1st and I have to let the clutch out and push it back in to get into 1st... but I really dont know which is why im asking... BTW Clutch/flywheel/tob were replaced at about 110,000 miles (year and a half ago) and I checked fluid in the T56, perfect level and light in color.

2) between 1500-2500 rpm there is a metallic slicing type noise (I dont know how else to describe it, sorry) which sounds like its coming from the tranny. Definitely not the engine and unlikely the rear end unless my ears are deceiving me. It kind of sounds like if you take 2 metal forks and rub them together. As far back as I can remember the car has always done this. Only does it under load. I think it may just be a heatshield rattling due to vibration at that specific rpm range, but if anybody has any insight as to what this may be, id appreciate it.

3) Lastly, and from what ive been able to gather this seems to be just one of those ls1 oddities, when cold there is a ticking sound that comes from the engine. happens at about 1-2 second intervals for about 8-10 minutes and then stops and engine runs smoothly. Ive been told by a number of people that their ls1 cars do the same thing. Again, this is something that has been going on as far back as I can remember.

Any info you guys can share regarding these issues would be GREATLY appreciated. And if you need me to answer any further questions about the car please just ask.

Thanks in advance.

 

number 3 sounds like a comman LS1 issue, some of the LS1's had piston dance in the cylinder so you would hear it "dance" or slightly move from side to side within the cylinder wall then when it is hot enough and it expands enough it goes away. thats what it sounds like and if it is your ok.

 

Number 1 and 2 might be related problems. When the clutch was replaced who did it? Did they replace the slave cylinder when they were in there? It might need a new slave, with that many miles its very possible. I had problems with the slave leaking and causing the clutch to slip. Before you tear into the tranny try replace the slave and bleed it down good, then your transmission might operate smoothly. Im not and expert, just taking a guess from my experiences. Good luck and let me know what you find out.

 

Thanks.. yeah thats what I heard about the piston just needing to warm up too... I appreciate it.

My mechanic is the guy who did the clutch. Ive had nothing but good experiences with him and he works on a lot of fbody's. The slave was not replaced to the best of my knowledge. although I will have to go back over my records to see if I can find the receipt from when I had the clutch done. But I am pretty sure that it was not replaced so I will have to look into that. Thank you.

 

correction... the noise im hearing from 1500-2500 rpm is present under no load while sitting in neutral in the driveway... but only when letting off throttle coming down from about 3000 rpm... but it is much less prominent than when under load.

 

ok... update time. I just took the car out for its first highway run in about a year, just to see what other bugs need to be worked out... here we go....

1) The grinding seems to happen when the clutch pedal is pushed fully down to the floor while the rpms are over 2k. It will keep grinding until the clutch pedal is pulled back up, even after the car has been put into neutral or another gear.

2) The metallic forks-rubbing-together type noise happens at exactly 1600 rpm in every gear, and it is quick, maybe only one second or less in duration. But it is very consistent, every gear, every time, 1600 rpm, accel & decel.

3) There is a constant chatter in 5th and 6th gear. No other gears have this chatter but it is constant in 5th and 6th. Not loud but definitely noticeable. When I wiggle the shifter left and right a little bit in gear (obviously not something I normally do but did in this case to see the reaction) The chatter changed tone, getting slightly lower sounding when shifter was moved to the left.

Also it sporadically doesnt want to go into first at a standstill, and I have to double-clutch it to get it into gear.

...Im pretty sure these are all clutch-related. Im thinking synchros but slave was suggested earlier and could make sense.... but Im lost at this point. far from an expert in these matters. Any input would be awesome. THANK YOU!

 

Not having an M6 I can't comment on the rest but having several manual cars # 1 sounds like the throwout/pilot bearing....

 

hmmm.... I guess thats possible, but TOB was replaced bout 15,000 miles ago. I do some pretty heavy city driving in Queens 2 or 3 times a week, so I guess it could be. I'm starting to get the idea I might need to replace the whole setup again... but this time with something a little stronger.. maybe monster clutch?

 

You should have really replaced the slave when you did the clutch, i would also suggest to replace the master also. It is getting up there and just had to replace mine. Both of my t56s make that rattling noise by the way at 1500rpm or so. It may only have 120k on it but the hydraulics are 11 years old though. The stock 98-00 slave and master are crap lol. If you get a monster clutch then you will need to replace both of them. The stock hydraulics have a hard time even pushing a LS7 clutch.

 

Thank you. I was wondering... if I replaced my clutch/fw/tob(minus the master & slave) 15,000 miles ago with a stock setup... would you recommend replacing everything all over again, or just the master & slave will do the trick.

Im just trying to get this car running right for the meantime. dont plan on doing any mods in the short term as I am headed to Afghanistan for a year within the next 6 months or so.

 

I would definitely do the master and slave. The clutch (as long as you haven't smelt it to much) should be good. I just replaced my master a couple weeks ago and glad I did, but replaced my slave when with a clutch that was in the car for about 12k or so. Clutch (LS7 kit) looked brand spanking new with no heat marks on the fly also when I had it out for my engine swap. There is a good chance that yours will look the same, and I beat the snot of my car for that 12k miles or so.